1ajr
From Proteopedia
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| - | [[Image:1ajr.jpg|left|200px]] | + | [[Image:1ajr.jpg|left|200px]] |
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| - | '''REFINEMENT AND COMPARISON OF THE CRYSTAL STRUCTURES OF PIG CYTOSOLIC ASPARTATE AMINOTRANSFERASE AND ITS COMPLEX WITH 2-METHYLASPARTATE''' | + | {{Structure |
| + | |PDB= 1ajr |SIZE=350|CAPTION= <scene name='initialview01'>1ajr</scene>, resolution 1.74Å | ||
| + | |SITE= <scene name='pdbsite=ACT:Coenzyme+Binding+Sites'>ACT</scene> | ||
| + | |LIGAND= | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Aspartate_transaminase Aspartate transaminase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.6.1.1 2.6.1.1] | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''REFINEMENT AND COMPARISON OF THE CRYSTAL STRUCTURES OF PIG CYTOSOLIC ASPARTATE AMINOTRANSFERASE AND ITS COMPLEX WITH 2-METHYLASPARTATE''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1AJR is a [ | + | 1AJR is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AJR OCA]. |
==Reference== | ==Reference== | ||
| - | Refinement and comparisons of the crystal structures of pig cytosolic aspartate aminotransferase and its complex with 2-methylaspartate., Rhee S, Silva MM, Hyde CC, Rogers PH, Metzler CM, Metzler DE, Arnone A, J Biol Chem. 1997 Jul 11;272(28):17293-302. PMID:[http:// | + | Refinement and comparisons of the crystal structures of pig cytosolic aspartate aminotransferase and its complex with 2-methylaspartate., Rhee S, Silva MM, Hyde CC, Rogers PH, Metzler CM, Metzler DE, Arnone A, J Biol Chem. 1997 Jul 11;272(28):17293-302. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9211866 9211866] |
[[Category: Aspartate transaminase]] | [[Category: Aspartate transaminase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: pig]] | [[Category: pig]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 09:58:35 2008'' |
Revision as of 07:58, 20 March 2008
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| , resolution 1.74Å | |||||||
|---|---|---|---|---|---|---|---|
| Sites: | |||||||
| Activity: | Aspartate transaminase, with EC number 2.6.1.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
REFINEMENT AND COMPARISON OF THE CRYSTAL STRUCTURES OF PIG CYTOSOLIC ASPARTATE AMINOTRANSFERASE AND ITS COMPLEX WITH 2-METHYLASPARTATE
Overview
Two high resolution crystal structures of cytosolic aspartate aminotransferase from pig heart provide additional insights into the stereochemical mechanism for ligand-induced conformational changes in this enzyme. Structures of the homodimeric native structure and its complex with the substrate analog 2-methylaspartate have been refined, respectively, with 1.74-A x-ray diffraction data to an R value of 0.170, and with 1.6-A data to an R value of 0.173. In the presence of 2-methylaspartate, one of the subunits (subunit 1) shows a ligand-induced conformational change that involves a large movement of the small domain (residues 12-49 and 327-412) to produce a "closed" conformation. No such transition is observed in the other subunit (subunit 2), because crystal lattice contacts lock it in an "open" conformation like that adopted by subunit 1 in the absence of substrate. By comparing the open and closed forms of cAspAT, we propose a stereochemical mechanism for the open-to-closed transition that involves the electrostatic neutralization of two active site arginine residues by the negative charges of the incoming substrate, a large change in the backbone (phi,psi) conformational angles of two key glycine residues, and the entropy-driven burial of a stretch of hydrophobic residues on the N-terminal helix. The calculated free energy for the burial of this "hydrophobic plug" appears to be sufficient to serve as the driving force for domain closure.
About this Structure
1AJR is a Single protein structure of sequence from Sus scrofa. Full crystallographic information is available from OCA.
Reference
Refinement and comparisons of the crystal structures of pig cytosolic aspartate aminotransferase and its complex with 2-methylaspartate., Rhee S, Silva MM, Hyde CC, Rogers PH, Metzler CM, Metzler DE, Arnone A, J Biol Chem. 1997 Jul 11;272(28):17293-302. PMID:9211866
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